Yep, I've seen 111 temp guages fail - happened to me when wire from sensor at cyl head got roasted from lack of insulation.

Did you hold the guage in your hand while it was wired to cylinder head sensor for testing? My guess is these guages are partially electric even on 111's, except maybe the oil pressure guage - so they need to be well grounded.

Later model 108, 114, 116's have circuit board type back on instrument clusters makin me think each guage has more complicated wiring than we realize.